Synthesis, structure and reactivity of the hexaphospha-titanocene, bis-(η5-3,5-di-tert-butyl-1,2,4-triphosphacyclopentadienyl)titanium(II)

Abstract

The novel, fully structurally characterised, 14e-titanocene [Ti(η⁵-(P₃C₂Bu^t₂)₂] made by (i) cocondensation of titanium vapour with the phosphaalkyne Bu^tCP (ii) reaction of Bu^tCP with [Ti(η⁶-C₆H₅Me)₂] at –78 ^°C or (iii) by heating TiCl_n with n(KP₃C₂Bu^t₂) (n = 2, 3) in toluene at 110 ^°C, undergoes an unusual [2+2] cycloaddition reaction with Bu^tCP to give [Ti(η⁵-P₃C₂Bu^t₂)(η³-η²-P₄C₃Bu^t₃)].